Solar electric power generation and wind force electric power generation are utilized as an outdoor electric power generator, but there is proposed an electric power generator which generates electric power utilizing pressure energy generated when a people walks or utilizing vibration energy generated when a vehicle or a train runs.
For example, patent document 1 proposes an electric power generating member including: a piezoelectric element having a plate-like piezoelectric ceramics and electrodes formed on both main surfaces of the piezoelectric ceramics; a press member which presses the piezoelectric element from the side of one of the main surfaces; and a support member which supports the piezoelectric element on the side of the other main surface. The support member supports a periphery of the piezoelectric element, and the press member presses the piezoelectric element by its flat press-surface inside of the support member. Therefore, the piezoelectric ceramics is sufficiently bent by pressure energy generated when a people walks or vibration energy generated when a vehicle runs, a large distortion can be obtained and cancellation of generated electric charge can be reduced. Therefore, high electric power can efficiently be obtained.
Patent document 2 discloses an electric power generating street light fixed to a high speed land bridge. This electric power generating street light includes a hollow cylindrical street light body which supports a display unit, and an electric power generating unit disposed in this street body. The electric power generating unit includes a piezoelectric element which generates electric power of the display unit by vibration of the high speed land bridge, and a flexible vibration plate fixed in a direction intersecting with an inner wall of the street light body. The piezoelectric element is fixed to a side surface of the vibration plate.